More robust platform definition support.

The idea is that someday it will be possible to just concatenate the entire
set of source files into a single giant source file, for systems that
want to work this way.  As a result, the build system now compiles every
file, although some of them will not have any definitions.

19 files changed, 237 insertions, 81 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4d28cb34..b4367365 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -28,6 +28,8 @@ set (NNG_SOURCES
     nng.h
 
     core/defs.h
+    core/init.c
+    core/init.h
     core/list.c
     core/list.h
     core/message.c
@@ -50,14 +52,15 @@ set (NNG_SOURCES
     core/transport.c
     core/transport.h
 
-    platform/posix/posix_alloc.h
-    platform/posix/posix_clock.h
-    platform/posix/posix_config.h
-    platform/posix/posix_debug.h
     platform/posix/posix_impl.h
-    platform/posix/posix_synch.h
-    platform/posix/posix_thread.h
-    platform/posix/posix_vsnprintf.h
+    platform/posix/posix_config.h
+
+    platform/posix/posix_alloc.c
+    platform/posix/posix_clock.c
+    platform/posix/posix_debug.c
+    platform/posix/posix_synch.c
+    platform/posix/posix_thread.c
+    platform/posix/posix_vsnprintf.c
 
     protocol/pair/pair.c
 
diff --git a/src/core/init.c b/src/core/init.c
new file mode 100644
index 00000000..4738a585
--- /dev/null
+++ b/src/core/init.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2016 Garrett D'Amore <garrett@damore.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "core/nng_impl.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+static int
+init_helper(void)
+{
+	/* This would be where we would initialize transports, etc. */
+	return (0);
+}
+
+int
+nni_init(void)
+{
+	return (nni_plat_init(init_helper));
+}
+
+void
+nni_fini(void)
+{
+	nni_plat_fini();
+}
diff --git a/src/core/init.h b/src/core/init.h
new file mode 100644
index 00000000..3a9221e4
--- /dev/null
+++ b/src/core/init.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2016 Garrett D'Amore <garrett@damore.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef CORE_INIT_H
+#define CORE_INIT_H
+
+#include "core/nng_impl.h"
+
+/*
+ * nni_init is called each time the user enters the library.  It ensures that
+ * the library is initlialized properly, and also deals with checks such as
+ * whether the process has forked since last initialization.
+ */
+extern int nni_init(void);
+
+/*
+ * nni_fini tears everything down.  In the future it may be used to ensure
+ * that all resources used by the library are released back to the system.
+ */
+extern void nni_fini(void);
+
+#endif /* CORE_INIT_H */
\ No newline at end of file
diff --git a/src/core/nng_impl.h b/src/core/nng_impl.h
index 4b62cfee..4d982113 100644
--- a/src/core/nng_impl.h
+++ b/src/core/nng_impl.h
@@ -40,6 +40,7 @@
 
 #include "core/defs.h"
 #include "core/list.h"
+#include "core/init.h"
 #include "core/message.h"
 #include "core/msgqueue.h"
 #include "core/panic.h"
diff --git a/src/core/panic.c b/src/core/panic.c
index 52dcb8c8..43c25beb 100644
--- a/src/core/panic.c
+++ b/src/core/panic.c
@@ -50,7 +50,7 @@ show_backtrace(void)
 			return;
 		}
 		for (i = 1; i < nframes; i++) {
-			nni_debug_out(lines[i]);
+			nni_println(lines[i]);
 		}
 	}
 #endif
@@ -75,10 +75,17 @@ nni_panic(const char *fmt, ...)
 	(void) nni_vsnprintf(buf, sizeof (buf), fbuf, va);
 	va_end(va);
 
-	nni_debug_out(buf);
-	nni_debug_out("This message is indicative of a BUG.");
-	nni_debug_out("Report this at http://github.com/nanomsg/nanomsg");
+	nni_println(buf);
+	nni_println("This message is indicative of a BUG.");
+	nni_println("Report this at http://github.com/nanomsg/nanomsg");
 
 	show_backtrace();
-	nni_abort();
+	nni_plat_abort();
+}
+
+void
+nni_println(const char *msg)
+{
+	/* TODO: support redirection of this later. */
+	nni_plat_println(msg);
 }
diff --git a/src/core/panic.h b/src/core/panic.h
index 6deef964..2dc65f8c 100644
--- a/src/core/panic.h
+++ b/src/core/panic.h
@@ -34,4 +34,13 @@
  */
 extern void nni_panic(const char *, ...);
 
+/*
+ * nni_println is used to print output to a debug console.  This should only
+ * be used in the most dire of circumstances -- such as during an assertion
+ * failure that is going to cause the program to crash.  After the string is
+ * emitted, a new line character is emitted, so the string should not
+ * include one.
+ */
+extern void nni_println(const char *);
+
 #endif	/* CORE_PANIC_H */
diff --git a/src/core/platform.c b/src/core/platform.c
index d96ebe70..dbdf3a7c 100644
--- a/src/core/platform.c
+++ b/src/core/platform.c
@@ -26,8 +26,10 @@
 
 #include "core/nng_impl.h"
 
+#if 0
 #if defined(PLATFORM_POSIX)
 #include "platform/posix/posix_impl.h"
 #else
 #error "unknown platform"
 #endif
+#endif
diff --git a/src/core/platform.h b/src/core/platform.h
index f7af7c30..230055c3 100644
--- a/src/core/platform.h
+++ b/src/core/platform.h
@@ -56,32 +56,23 @@
  */
 
 /*
- * nni_abort crashes the system; it should do whatever is appropriate
+ * nni_plat_abort crashes the system; it should do whatever is appropriate
  * for abnormal programs on the platform, such as calling abort().
  */
-void nni_abort(void);
+extern void nni_plat_abort(void);
 
 /*
- * nni_vnsprintf is exactly like its POSIX counterpart.
+ * nni_plat_vnsprintf is exactly like its POSIX counterpart.
  * Some platforms (Windows!) need a special version of this.
  */
-void nni_vsnprintf(char *, size_t, const char *, va_list);
+extern void nni_plat_vsnprintf(char *, size_t, const char *, va_list);
 
 /*
- * nni_debug_output is used to emit debug messages.  Typically this is used
+ * nni_plat_println is used to emit debug messages.  Typically this is used
  * during core debugging, or to emit panic messages.  Message content will
  * not contain newlines, but the output will add them.
  */
-void nni_debug_out(const char *);
-
-/*
- * nni_set_debug_output is used to redirect debug output; for example an
- * application could replace the default output routine with one that sends
- * it's output to syslog.  If NULL is specified, then a default handler
- * used instead.  The handler should add any newlines to the output as
- * required.  The default handler writes to standard error.
- */
-void nni_set_debug_out(void (*)(const char *));
+extern void nni_plat_println(const char *);
 
 /*
  * nni_alloc allocates memory.  In most cases this can just be malloc().
@@ -89,7 +80,7 @@ void nni_set_debug_out(void (*)(const char *));
  * possible to use a slab allocator or somesuch.  It is permissible for this
  * to return NULL if memory cannot be allocated.
  */
-void *nni_alloc(size_t);
+extern void *nni_alloc(size_t);
 
 /*
  * nni_free frees memory allocated with nni_alloc. It takes a size because
@@ -99,7 +90,7 @@ void *nni_alloc(size_t);
  * This routine does nothing if supplied with a NULL pointer and zero size.
  * Most implementations can just call free() here.
  */
-void nni_free(void *, size_t);
+extern void nni_free(void *, size_t);
 
 typedef struct nni_mutex *nni_mutex_t;
 typedef struct nni_cond *nni_cond_t;
@@ -107,32 +98,32 @@ typedef struct nni_cond *nni_cond_t;
 /*
  * Mutex handling.
  */
-int nni_mutex_create(nni_mutex_t *);
-void nni_mutex_destroy(nni_mutex_t);
-void nni_mutex_enter(nni_mutex_t);
-void nni_mutex_exit(nni_mutex_t);
-int nni_mutex_tryenter(nni_mutex_t);
+extern int nni_mutex_create(nni_mutex_t *);
+extern void nni_mutex_destroy(nni_mutex_t);
+extern void nni_mutex_enter(nni_mutex_t);
+extern void nni_mutex_exit(nni_mutex_t);
+extern int nni_mutex_tryenter(nni_mutex_t);
 
-int nni_cond_create(nni_cond_t *, nni_mutex_t);
-void nni_cond_destroy(nni_cond_t);
+extern int nni_cond_create(nni_cond_t *, nni_mutex_t);
+extern void nni_cond_destroy(nni_cond_t);
 
 /*
  * nni_cond_broadcast wakes all waiters on the condition.  This should be
  * called with the lock held.
  */
-void nni_cond_broadcast(nni_cond_t);
+extern void nni_cond_broadcast(nni_cond_t);
 
 /*
  * nni_cond_signal wakes a signal waiter.
  */
-void nni_cond_signal(nni_cond_t);
+extern void nni_cond_signal(nni_cond_t);
 
 /*
  * nni_condwait waits for a wake up on the condition variable.  The
  * associated lock is atomically released and reacquired upon wake up.
  * Callers can be spuriously woken.  The associated lock must be held.
  */
-void nni_cond_wait(nni_cond_t);
+extern void nni_cond_wait(nni_cond_t);
 
 /*
  * nni_cond_timedwait waits for a wakeup on the condition variable, just
@@ -143,33 +134,33 @@ void nni_cond_wait(nni_cond_t);
  * can be NNG_ETIMEDOUT.  Note that it is permissible to wait for longer
  * than the timeout based on the resolution of your system clock.
  */
-int nni_cond_timedwait(nni_cond_t, uint64_t);
+extern int nni_cond_timedwait(nni_cond_t, uint64_t);
 
 typedef struct nni_thread *nni_thread_t;
 /*
  * nni_thread_creates a thread that runs the given function. The thread
  * receives a single argument.
  */
-int nni_thread_create(nni_thread_t *, void (*fn)(void *), void *);
+extern int nni_thread_create(nni_thread_t *, void (*fn)(void *), void *);
 
 /*
  * nni_thread_reap waits for the thread to exit, and then releases any
  * resources associated with the thread.  After this returns, it
  * is an error to reference the thread in any further way.
  */
-void nni_thread_reap(nni_thread_t);
+extern void nni_thread_reap(nni_thread_t);
 
 /*
  * nn_clock returns a number of microseconds since some arbitrary time
  * in the past.  The values returned by nni_clock may be used with
  * nni_cond_timedwait.
  */
-uint64_t nni_clock(void);
+extern uint64_t nni_clock(void);
 
 /*
  * nni_usleep sleeps for the specified number of microseconds (at least).
  */
-void nni_usleep(uint64_t);
+extern void nni_usleep(uint64_t);
 
 /*
  * nni_platform_init is called to allow the platform the chance to
@@ -178,15 +169,27 @@ void nni_usleep(uint64_t);
  * may be called at any point thereafter.  It is permitted to return
  * an error if some critical failure inializing the platform occurs,
  * but once this succeeds, all future calls must succeed as well, unless
- * nni_fini has been called.
+ * nni_plat_fini has been called.
+ *
+ * The function argument should be called if the platform has not initialized
+ * (i.e. exactly once please), and its result passed back to the caller.
  */
-int nni_platform_init(void);
+extern int nni_plat_init(int (*)(void));
 
 /*
  * nni_platform_fini is called to clean up resources.  It is intended to
  * be called as the last thing executed in the library, and no other functions
  * will be called until nni_platform_init is called.
  */
-void nni_platform_fini(void);
+extern void nni_plat_fini(void);
+
+/*
+ * Actual platforms we support.
+ */
+#if defined(PLATFORM_POSIX)
+#include "platform/posix/posix_impl.h"
+#else
+#error "unknown platform"
+#endif
 
 #endif /* CORE_PLATFORM_H */
diff --git a/src/core/snprintf.c b/src/core/snprintf.c
index 574d537a..004916a2 100644
--- a/src/core/snprintf.c
+++ b/src/core/snprintf.c
@@ -34,3 +34,9 @@ nni_snprintf(char *dst, size_t sz, const char *fmt, ...)
 	nni_vsnprintf(dst, sz, fmt, va);
 	va_end(va);
 }
+
+void
+nni_vsnprintf(char *dst, size_t sz, const char *fmt, va_list va)
+{
+	nni_plat_vsnprintf(dst, sz, fmt, va);
+}
diff --git a/src/core/snprintf.h b/src/core/snprintf.h
index b98b6ee7..12d7f207 100644
--- a/src/core/snprintf.h
+++ b/src/core/snprintf.h
@@ -31,5 +31,6 @@
  * from the platform.
  */
 extern void nni_snprintf(char *, size_t, const char *, ...);
+extern void nni_vsnprintf(char *, size_t, const char *, va_list);
 
 #endif	/* CORE_SNPRINTF_H */
diff --git a/src/core/socket.c b/src/core/socket.c
index f5904823..094f9ce0 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -110,8 +110,8 @@ nni_socket_close(nni_socket_t sock)
 	 */
 
 	/* XXX: close remaining pipes */
-	while ((pipe = nni_list_first(&sock->nn_pipes)) != NULL) {
-		nni_list_remove(&sock->nn_pipes, pipe);
+	while ((pipe = nni_list_first(&sock->s_pipes)) != NULL) {
+		nni_list_remove(&sock->s_pipes, pipe);
 		/* XXX: call nni_pipe_close, then nni_pipe_destroy */
 	}
 
diff --git a/src/nng.c b/src/nng.c
index 123c69bd..9b10c3b1 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -36,21 +36,27 @@
 int
 nng_socket_create(nng_socket_t *s, uint16_t proto)
 {
-	nni_platform_init();
+	int rv;
+	if ((rv = nni_init()) != 0) {
+		return (rv);
+	}
 	return (nni_socket_create(s, proto));
 }
 
 int
 nng_socket_close(nng_socket_t s)
 {
-	nni_platform_init();
+	int rv;
+	if ((rv = nni_init()) != 0) {
+		return (rv);
+	}
 	return (nni_socket_close(s));
 }
 
 uint16_t
 nng_socket_protocol(nng_socket_t s)
 {
-	nni_platform_init();
+	nni_init();
 	return (nni_socket_protocol(s));
 }
 
@@ -61,6 +67,7 @@ nng_socket_protocol(nng_socket_t s)
 const char *
 nng_strerror(int num)
 {
+	nni_init();
 	switch (num) {
 	case 0:
 		return ("Hunky dory");	/* what did you expect? */
@@ -96,13 +103,16 @@ nng_strerror(int num)
 int
 nng_msg_alloc(nng_msg_t *msgp, size_t size)
 {
-        nni_platform_init();
+	int rv;
+	if ((rv = nni_init()) != 0) {
+		return (rv);
+	}
         return (nni_msg_alloc(msgp, size));
 }
 
 void
 nng_msg_free(nng_msg_t msg)
 {
-        nni_platform_init();
+        nni_init();
         return (nni_msg_free(msg));
 }
\ No newline at end of file
diff --git a/src/platform/posix/posix_alloc.h b/src/platform/posix/posix_alloc.c
index 8451cc9c..b47a95b2 100644
--- a/src/platform/posix/posix_alloc.h
+++ b/src/platform/posix/posix_alloc.c
@@ -27,6 +27,12 @@
  * get multiple symbols defined.
  */
 
+#include "core/nng_impl.h"
+
+#ifdef PLATFORM_POSIX_ALLOC
+
+#include <stdlib.h>
+
 /*
  * POSIX memory allocation.  This is pretty much standard C.
  */
@@ -43,3 +49,5 @@ nni_free(void *ptr, size_t size)
 	NNI_ARG_UNUSED(size);
 	free(ptr);
 }
+
+#endif
\ No newline at end of file
diff --git a/src/platform/posix/posix_clock.h b/src/platform/posix/posix_clock.c
index 07fc603d..c772263c 100644
--- a/src/platform/posix/posix_clock.h
+++ b/src/platform/posix/posix_clock.c
@@ -30,6 +30,9 @@
 /*
  * POSIX clock stuff.
  */
+#include "core/nng_impl.h"
+
+#ifdef PLATFORM_POSIX_CLOCK
 
 #include <time.h>
 #include <errno.h>
@@ -147,3 +150,5 @@ nni_usleep(uint64_t usec)
 }
 
 #endif	/* NNG_USE_GETTIMEOFDAY */
+
+#endif	/* PLATFORM_POSIX_CLOCK */
diff --git a/src/platform/posix/posix_debug.h b/src/platform/posix/posix_debug.c
index d25a6c11..6b2d875a 100644
--- a/src/platform/posix/posix_debug.h
+++ b/src/platform/posix/posix_debug.c
@@ -20,29 +20,23 @@
  * IN THE SOFTWARE.
  */
 
+#include "core/nng_impl.h"
+
+#ifdef PLATFORM_POSIX_DEBUG
+
 #include <stdlib.h>
 #include <stdio.h>
 
-void (*debug_out)(const char *line);
-
 void
-nni_abort(void)
+nni_plat_abort(void)
 {
 	abort();
 }
 
 void
-nni_debug_out(const char *message)
+nni_plat_println(const char *message)
 {
-	if (debug_out != NULL) {
-		debug_out(message);
-	} else {
-		(void) fprintf(stderr, "%s\n", message);
-	}
+	(void) fprintf(stderr, "%s\n", message);
 }
 
-void
-nni_set_debug_out(void (*out)(const char *))
-{
-	debug_out = out;
-}
+#endif /* PLATFORM_POSIX_DEBUG */
\ No newline at end of file
diff --git a/src/platform/posix/posix_impl.h b/src/platform/posix/posix_impl.h
index 60a1d663..48b6e99b 100644
--- a/src/platform/posix/posix_impl.h
+++ b/src/platform/posix/posix_impl.h
@@ -31,11 +31,12 @@
  */
 
 #ifdef	PLATFORM_POSIX
+#define PLATFORM_POSIX_ALLOC
+#define PLATFORM_POSIX_DEBUG
+#define PLATFORM_POSIX_CLOCK
+#define PLATFORM_POSIX_SYNCH
+#define PLATFORM_POSIX_THREAD
+#define PLATFORM_POSIX_VSNPRINTF
+
 #include "platform/posix/posix_config.h"
-#include "platform/posix/posix_debug.h"
-#include "platform/posix/posix_alloc.h"
-#include "platform/posix/posix_clock.h"
-#include "platform/posix/posix_synch.h"
-#include "platform/posix/posix_thread.h"
-#include "platform/posix/posix_vsnprintf.h"
 #endif
diff --git a/src/platform/posix/posix_synch.h b/src/platform/posix/posix_synch.c
index d3e44411..cb8b30dd 100644
--- a/src/platform/posix/posix_synch.h
+++ b/src/platform/posix/posix_synch.c
@@ -32,6 +32,10 @@
  * pthreads.
  */
 
+#include "core/nng_impl.h"
+
+#ifdef PLATFORM_POSIX_SYNCH
+
 #include <pthread.h>
 #include <time.h>
 
@@ -235,3 +239,5 @@ nni_cond_timedwait(nni_cond_t c, uint64_t usec)
 	}
 	return (0);
 }
+
+#endif
\ No newline at end of file
diff --git a/src/platform/posix/posix_thread.h b/src/platform/posix/posix_thread.c
index 27ad888f..a41c7e7c 100644
--- a/src/platform/posix/posix_thread.h
+++ b/src/platform/posix/posix_thread.c
@@ -31,6 +31,10 @@
  * POSIX threads.
  */
 
+#include "core/nng_impl.h"
+
+#ifdef PLATFORM_POSIX_THREAD
+
 #include <pthread.h>
 #include <time.h>
 #include <string.h>
@@ -66,7 +70,7 @@ nni_thread_create(nni_thread_t *tp, void (*fn)(void *), void *arg)
 	thr->func = fn;
 	thr->arg = arg;
 
-	if ((rv = pthread_create(&thr->tid, thr, thrfunc, arg)) != 0) {
+	if ((rv = pthread_create(&thr->tid, NULL, thrfunc, thr)) != 0) {
 		nni_free(thr, sizeof (*thr));
 		return (NNG_ENOMEM);
 	}
@@ -91,8 +95,9 @@ atfork_child(void)
 }
 
 int
-nni_platform_init(void)
+nni_plat_init(int (*helper)(void))
 {
+	int rv;
 	if (plat_fork) {
 		nni_panic("nng is fork-reentrant safe");
 	}
@@ -108,14 +113,18 @@ nni_platform_init(void)
 		pthread_mutex_unlock(&plat_lock);
 		return (NNG_ENOMEM);
 	}
-	plat_init = 1;
+	if ((rv = helper()) == 0) {
+		plat_init = 1;
+	}
 	pthread_mutex_unlock(&plat_lock);
 
-	return (0);
+	return (rv);
 }
 
 void
-nni_platform_fini(void)
+nni_plat_fini(void)
 {
 	/* XXX: NOTHING *YET* */
-}
\ No newline at end of file
+}
+
+#endif
\ No newline at end of file
diff --git a/src/platform/posix/posix_vsnprintf.h b/src/platform/posix/posix_vsnprintf.c
index 8270d255..42367b4c 100644
--- a/src/platform/posix/posix_vsnprintf.h
+++ b/src/platform/posix/posix_vsnprintf.c
@@ -20,11 +20,17 @@
  * IN THE SOFTWARE.
  */
 
+#include "core/nng_impl.h"
+
+#ifdef PLATFORM_POSIX_VSNPRINTF
+
 #include <stdarg.h>
 #include <stdio.h>
 
 void
-nni_vsnprintf(char *dst, size_t sz, const char *fmt, va_list va)
+nni_plat_vsnprintf(char *dst, size_t sz, const char *fmt, va_list va)
 {
 	(void) vsnprintf(dst, sz, fmt, va);
 }
+
+#endif
\ No newline at end of file